Relative effectiveness and validity of mood induction procedures: a metaanalysis
RAINER WESTERMANN E r n s t -M o r i~-~n~-U n i v e r s i~tAbstract The effectiveness and validity of I I important mood induction procedures (MIPs) were comparatively evaluated by meta-analyticalprocedures. Two hundred andfifty effects of the experimental induction ofpositive, elated and negative, depressed mood in adult, nonclinical samples were integrated. Effect sizes were generally larger for negative than for positive mood inductions. Thepresentation of afilm or story turnedout to be most effective in inducing both positive and negative mood states. The effects are especially large when subjects are explicitly instructed to enter the specified mood state. For elated mood, all other MIPs yielded considerably lower effectiveness scores. For the induction of negative mood states, Imagination, Velten, Music. Social Interaction and Feedback MIPs were about as effective as the Film/Story MIP without instruction. Induction effects covaried with several study characteristics. Effects tend to be smaller when demand characteristics are controlled or subjects are not informed about the purpose of the experiment. For The authors thank several anonymous reviewers for valuable comments on earlier versions of this article, and Andrea Riihenbeck and Sebastian Krapoth for help with the literature analysis. 558 R. Westermann et al. behavioural measures, effects are smaller than for self-reports but still larger than zero. Hence, the effects of MIPS can be partly, but not fully due to &mand effects. 'List of selected journals: Archiv ftir Quarterly. Zeitschrqt ftir experimentelle wrd angewandte Psychologie, Zeitschrgt ftir Sozialpsychologie. 2No relevant studies were found in Memory and Cognition, Psychosomatic Medicine, and Scandinavian Journal of Psychology. The complete reference list is available on request from the first author.